Cyphomyrus discorhynchus ( Peters, 1852 )

Kramer, Bernd & Bank, F. Herman Van der, 2011, The Victoria Falls, a species boundary for the Zambezi Parrotfish, Cyphomyrus discorhynchus (Peters, 1852), and the resurrection of Cyphomyrus cubangoensis (Pellegrin, 1936) (Mormyridae: Teleostei), Journal of Natural History 45 (43 - 44), pp. 2669-2699 : 2689-2690

Cyphomyrus discorhynchus ( Peters, 1852)

( Figure 1G )

Nominal species in boldface.

Mormyrus discorhynchus Peters, 1852: 275 .

Petrocephalus discorhynchus: Marcusen 1864: 150 .

Mormyrus (Petrocephalus) discorhynchus: Sauvage 1880: 27 .

Marcusenius discorhynchus: Boulenger 1898: 797 .

Cyphomyrus discorhynchus: Myers 1960: 125 , Van der Bank and Kramer 1996: 287; Skelton 2001: 97; Lavoué et al. 2003: 288; Kramer and Swartz 2010: 228, fig. 8.

Hippopotamyrus discorhynchus: Taverne 1971a: 104 ; Seegers 1996: 68.

Marcusenius tanganicanus Boulenger, 1906: 455 , pl. 30, fig. 1; Boulenger 1909: 81 (synonymy with Mormyrus discorhynchus ).

Marcusenius smithersi Määr, 1962 .

Cyphomyrus smithersi: Jubb 1967: 33

Hippopotamyrus smithersi: Taverne 1971a: 104 .

Material examined

See Material and methods section.

Type specimens. ZMB 3.674 , lectotype. Paralectotypes: individuals ZMB 3.673 , ZMB 3.675 , ZMB 3.676 . ZMB 23.374 , one paralectotype plus remnants of a dissected specimen; all collected by W.C. Peters. Lectotype and paralectotypes designated by Seegers (1996: 69).

Type locality. “Mossambique”. In his 1868 publication, Peters specified that the origin of his specimens was “Tette” (present spelling Tete) on the Zambezi , and “the Licuare in Boror” (the Licuare is a short coastal river on the northern periphery of the Zambezi delta, discharging into the Indian Ocean at Quelimane ; all Mozambique). Tete is below the Cahora Bassa dam, and separated from the Indian Ocean by 400 km .

Diagnosis

nD, median 33–34 (range 28–36); nA, median 24–25 (range 23–27); SPc, median 12 (range 12–13); SLS, median 64–69 (range 57–72); LD, mean 0.2977 –0.3129 (range 0.2701 –0.3239) of SL; LA, mean 0.2040 –0.2124 (range 0.1844 –0.2263) of SL; CPL, mean 0.2154 –0.2215 (range 0.2066 –0.2405) of SL; CPD, mean 0.2952 –0.3002 (range 0.2657 –0.3380) of CPL; BD, mean 0.2841 –0.3530 (range 0.2464 –0.3407) of SL; PDL, mean 0.5631 –0.5779 (range 0.5455 –0.6065) of SL; HL, mean, 0.2197 –0.2373 (range 0.2168 –0.2639) of SL. Bipolar EOD, of 130 µs duration (n = 1).

Remarks

Seegers (1996) gives a lively description of ecology and biology of specimens caught on or near Lake Rukwa.

For distinguishing between specimens of C. discorhynchus and C. cubangoensis , the most useful anatomical characters are: longer LD, longer LA, higher number of nD and nA, higher CPD/CPL in C. discorhynchus than C. cubangoensis .

Figures

Figure 1. Members of the Cyphomyrus discorhynchus species complex. (A) Marcusenius cubangoensis Pellegrin 1936, Upper Okavango River, Angola (NMB 5216, syntype); (B) Cyphomyrus cubangoensis (Pellegrin, 1936), Namibia: province Kavango: Okavango River (SAIAB 20384 specimen R1); (C) C. cubangoensis (Pellegrin, 1936), Namibia: Caprivi Strip: Kwando River: